1. Field of the Invention
The subject invention relates to battery compartments which include means for preventing electrical contact with both terminals of a battery if the battery is improperly aligned during insertion into the compartment.
2. Description of Prior Art
Battery compartments or holders which receive batteries regardless of polarity orientation but which provide electrical continuity only when batteries are inserted in a predetermined way are well known. In fact, U.S. Pat. Nos. 2,397,469 and 3,984,256 disclose apparatus of this type.
U.S. Pat. No. 2,397,469 discloses a battery holder having a U-shaped metallic bracket. One end of the bracket supports a socket manufactured from an insulating material and a conductor recessed in the socket. The other end of the bracket supports a conical spring contact which is soldered thereto. In operation, the spring contact abuts one end of a battery and urges a protruding terminal at its other end into engagement with the recessed contact. If the battery is inserted in an opposite direction, the recessed contact is not engaged.
U.S. Pat. No. 3,984,256 discloses an electrical device having a battery compartment for receipt of a battery having a protruding terminal on one end, and a cover for closure of the compartment. An insulated key ring and a contact disc are located in the compartment for making electrical contact with the protruding terminal when the battery is inserted in the compartment with the correct polarity orientation and for preventing electric contact with the protruding terminal when the battery is inserted in the compartment with incorrect polarity orientation. The structure permits closure of the compartment with the battery having correct or incorrect polarity orientation. The insulated key ring has an interior diameter greater than the diameter of the protruding terminal and the contact disk extends beyond the interior diameter to readily permit engagement by the terminal. The contact disk includes a number of springs which urge it towards the compartment opening so that when a battery is inserted in the compartment with correct polarity orientation, the protruding terminal contacts the contact disk and, when the battery is inserted in the compartment with incorrect polarity orientation, the battery case engages the insulated key ring without electric engagement with the contact disk, thereby preventing electrical continuity.